Amanda Kennedy, founder of Sassybax shapewear, has been granted a US patent for a knit structure developed to create gravity-defying support in leggings and underwear.

The pants, called Sassybax Leggings and Long Leg Panty, are woven with shaping cups to lift, round and separate the buttocks. Sassybax also produces a bra line that smoothes a woman's back.

The design incorporates eight distinct knitting techniques woven on customised Santoni machines that are used to manufacture seamless garments.

"Often women need to combat more than pantyline troubles; they need to fight gravity," said Kennedy.

The company estimates that intimate apparel alone is a US$9.6bn industry and growing.